[1] Musepack was developed using the MP2 codec as a starting point, but many features have since been added, including: The psychoacoustic model of MPC is based on MPEG ISO model 2, but is extended by CVD (clear voice detection).
The quantization algorithm of the MPC encoder performs spectral shaping of the noise, called adaptive noise shaping (ANS), in order to overcome the low frequency resolution of the polyphase quadrature filter bands.
Nevertheless, various listening tests have been conducted in which Musepack has performed well at both lower and higher bitrates.
In May 2004, a series of double-blind listening tests[5] (as reported on Slashdot[6]) suggested that Musepack and Ogg Vorbis (which was the 1.1 "aoTuV" fork at the time) were the two best available codecs for high-quality audio compression at bitrates around 128 kbit/s, beating MP3, AAC, WMA, and ATRAC.
All devices with software audio decoding that are supported by Rockbox, including older revisions of iPod, can also play Musepack files.